The Big Melt in World Ocean Ice Record

Sea ice extent in both the northern and southern hemisphere was at record low levels for the month of January 2017.

Last month set a record for the lowest sea-ice extent for the month, falling below the record set last year, according to the National Snow and Ice Data Center (NSIDC), a Colorado-based research outfit.

Arctic sea ice this January averaged 5.17 million square miles, the lowest for the month in the 38-year sea ice record.

"Greenhouse gases emitted through human activities and the resulting increase in global mean temperatures are the most likely underlying cause of the sea ice decline," the snow and ice data center said.

Sea ice extent was also tracking at record low levels for the month of January in the Antarctic, which is currently still in summer.

“I started doing Arctic climate work back in 1982 as a young graduate student,” a report in National Geographic quoted Mark Serreze, the director of the National Snow and Ice Data Center in Boulder, Colorado as saying. “So I’ve been looking at the Arctic for a long time, and I have never seen anything like this.”

The NSIDC cited the analysis of a NASA researcher, Richard Cullather, who found that the winter of 2015-2016 was the warmest on record in the Arctic during the satellite era, which began there in 1979.

It's unclear if 2017 will rank higher, given the whims of natural weather variability and the long-term influence of human-caused global warming.

Antarctic ice fluctuates wildly year to year, and the link to man-made global warming there is not clear, a report in USA Today qouted NASA ice expert Walt Meier as saying.